At least three opposition party leaders have had their names falsely registered as being interested in buying shares in Mighty River Power.
Labour's David Shearer and the Greens' Metiria Turei and Russel Norman all say they've received emails informing them they have been pre-registered.
This is the initial part of the share sale process through which the Government can gauge the level of support from New Zealanders.
Dr Norman says Treasury told him that it had been done in jest, but the Greens' co-leader questions how they knew the intent of whoever signed him up.
The Government says that 290,000 New Zealanders have pre-registered their interest in the partial share float of the state-owned energy company.
Shonky process - Shearer
Mr Shearer opposes the asset sales and said he does not know how his name was put down for pre-registration.
"The fact that my name has been put up as interested in buying shares just shows how shonky this process actually is. Whose dog and cat and next door neighbour has been signed up without them knowing?"
Mr Shearer said he will be investigating how he was signed up for the shares.
Finance Minister Bill English suggests the sign-up of opposition leaders could be a stunt by their parties.
Opposition parties and unions today presented a petition against partial asset sales to Parliament.
Mr English says the parties themselves could have engineered the apparently false sign-ups.